The third season of the American sitcom The Big Bang Theory aired on CBS from September 21, 2009 to May 24, 2010. It received higher ratings than the previous two seasons with over 15 million viewers. The third season saw the first appearances of future main cast members Melissa Rauch and Mayim Bialik as Bernadette Rostenkowski and Dr. Amy Farrah Fowler respectively. Christine Baranski was nominated for the Primetime Emmy Award for Outstanding Guest Actress in a Comedy Series at the 62nd Primetime Emmy Awards for the episode, "The Maternal Congruence". Jim Parsons won the Primetime Emmy Award for Outstanding Lead Actor in a Comedy Series for the episode "The Pants Alternative". Cast Main cast Johnny Galecki as Leonard Hofstadter Jim Parsons as Sheldon Cooper Kaley Cuoco as Penny Simon Helberg as Howard Wolowitz Kunal Nayyar as Rajesh Ramayan Koothrappali Recurring cast Laurie Metcalf as Mary Cooper Carol Ann Susi as Mrs. Wolowitz John Ross Bowie as Dr. Barry Kripke Wil Wheaton as himself Kevin Sussman as Stuart Bloom Melissa Rauch as Bernadette Rostenkowski Brian George as Dr. V.M. Koothrappali Alice Amter as Mrs. Koothrappali Christine Baranski as Dr. Beverly Hofstadter Sara Gilbert as Leslie Winkle Brian Thomas Smith as Zack Johnson Guest cast Lewis Black as Professor Crawley Molly Morgan as Bethany Sarah Buehler as Sarah Andy Mackenzie as Skeeter Elizabeth Bogush as Dr. Catherine Millstone Oliver Muirhead as Professor Laughlin Zachary Abel as Todd Jason Mesches as Denny Danica McKellar as Abby Jen Drohan as Martha Julio Oscar Mechoso as Officer Hackett Yeardley Smith as Sandy Kevin Brief as Glenn Steve Paymer as Judge Kirby Marcus Folmar as Guard Frank Maharajh as Venkatesh Koothrappali Judy Greer as Dr. Elizabeth Plimpton Ally Maki as Joyce Kim Steven Yeun as Sebastian Ajgie Kirkland as Louie/Louise Lauri Johnson as Mrs. Gunderson Mayim Bialik as Dr. Amy Farrah Fowler Special guest cast Katee Sackhoff as herself Ira Flatow as himself Stan Lee as himself James Earl Jones as himself Stephen Hawking as himself Elon Musk as himself Episodes Ratings Reception The third season received critical acclaim. Maureen Ryan of Chicago Tribune who wrote that "Big Bang Theory, which is in its third season, is doing many things very right", Alan Sepinwall of The Star-Ledger wrote "the Penny/Sheldon interaction was gold, as always", and Ken Tucker of Entertainment Weekly, who wrote that "what lifts The Big Bang Theory into frequent excellence is its